The dynamic analysis of inelastic structures with geometric nonlinearities experiencing large deformations and buckling are challenging in particular if three dimensional space effects are considered. Shaking table testing performed by the authors on a braced steel frame model structure with a "zipper" mechanism provides benchmark information and challenge for design and analysis. The paper describes the challenges and successful monitoring of dynamic behavior with progressively expending buckling and fractures in various elements of the "zipper" mechanism. Moreover, the paper shows conditions for which the mechanism is successful to achieve its designed performance and the conditions when it cannot achieve it. The paper introduces a new formulation of a three dimensional beam column element and the associated analysis of the global frame system using a corotational approach formulated in the state space. The corotational approach may allow uncoupling of the local large deformations and inelastic buckling of the element from the large deformation of the global system. The performance of the new analytical formulation seems to be able to capture the progressive buckling leading to damage and collapse.
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